I guess if he scores one, he'll just radio ahead to the rest of the trap.
Posted on 05/01/2005 6:19:00 AM PDT by MississippiMasterpiece
President Bush made it clear last week that he sees no quick fixes to the nation's energy woes. The problem has been long in coming, the argument goes, and so will the solutions. But if history is any guide, there is one thing he could do immediately: bring back the 55 miles-per-hour speed limit.
It has been done before. Along with record oil and gasoline prices, improvements in fuel efficiency and a lasting economic recession, speed limits helped curb fuel consumption for the first time in American postwar history between 1974 and 1984.
Of course, energy eventually became cheap again, the economy expanded and Americans became complacent and unwilling to make more sacrifices.
Instead of opting for small fuel-efficient cars, people switched to large sport utility vehicles and larger pickups. As drivers groaned and states fought for their right to speed, the limit was raised.
While oil consumption in most industrialized nations has either leveled off or declined, in the United States, oil demand has soared 38 percent since the first oil shock of 1973.
The Bush administration's focus over the last four years has been to increase the supply of oil and natural gas, which are also priorities for the energy industry, instead of finding ways to cut back on energy demand, which until very recently has been left out of the picture.
"We are in a boxing match, and the president keeps one hand tied to his back," said Steven Nadel, the executive director for the American Council for an Energy-Efficient Economy, a nonprofit research group in Washington. "We're punching with supplies and not using demand. We're at a disadvantage."
Other industrialized countries, especially in Europe, have been much more successful than the United States and have managed to actually lower oil demand, or at least keep it in check. That comes from higher diesel use and higher taxes. In France and Germany, a gallon of gasoline sells for as much as $6, with taxes accounting for about 80 percent of that.
Few politicians in America might risk ridicule or rejection by explicitly supporting higher taxes on gasoline, one of the surest ways to limit the nation's dependence on oil.
"Even the least outrageous gasoline tax would have choked off some demand, and the money would have gone to our own government instead of being transferred overseas," said Robert K. Kaufmann, a professor of geography at the Center for Energy and Environmental Studies at Boston University. "Of course, that would have to involve personal sacrifice, which is off the table politically."
There are other ways to curb consumption that may be only slightly less challenging, analysts say. One would be to increase the average mileage per gallon requirement. After Congress passed legislation forcing automakers to act in 1975, average mileage almost doubled to 27.5 miles a gallon in 1987 from 14 in 1972. But it has since slipped back to 24 because of S.U.V.'s, and Congress shows no inclination to toughen the standards.
Another way to sharply reduce demand - and improve mileage - would be to encourage drivers to buy diesel cars, which offer as much as 60 percent more fuel efficiency, said Theodore R. Eck, an energy consultant and former chief economist at the Amoco oil company.
"The neat thing here is that this is off-the-shelf technology," he said. But the trade-off to diesel fuels also includes higher emissions of nitrate oxide, a pollutant that is responsible for smog.
In a recent speech, President Bush suggested that diesel cars might be made eligible for similar income tax credits as hybrid cars, which are quickly turning into best sellers with long waiting lists.
The present predicament behind high oil prices is quite different than the oil shocks of the 1970's and 1980's, which were a result of producers in the Organization of Petroleum Exporting Countries cutting oil supplies. Today, the price shock comes from rapidly increasing demand, driven largely by China, but also by the United States and its strong car culture.
After rising 33 percent in the last year, crude oil prices in New York slipped below $50 a barrel on Friday for the first time in 10 weeks. They closed down nearly 4 percent at $49.72 a barrel.
Still, Americans can expect to pay record prices for gasoline this summer. According to the latest national average compiled by the Energy Department, gasoline prices at the pump averaged $2.24 a gallon, up 42 cents from last year; they are expected to touch a record $2.35 a gallon this summer.
Polls show that higher gasoline prices are increasingly hurting Americans, and the president is pressing Congress to revive an energy bill that has been stalled for four years.
Since the last energy shock of the 1980's, the economy as a whole has shifted toward services and away from heavy industry and is now less dependent on oil than it once was. But that has been more than offset by the rise of oil demand for the transportation sector, which accounts for two of every three barrels of crude oil consumed here; gasoline alone amounts to half the nation's oil consumption.
"We've had this situation building up for years, and yet the focus continues to be on the very long term," said Shirley Neff, an adjunct professor at Columbia University and a former economist on the Senate Energy Committee. "We have to focus on demand and be more efficient in our energy use. We need something like an Apollo program for the transportation sector."
But restricting demand might also weaken economic growth, an unpalatable prospect for any government, especially at a time when some are already blaming energy costs for a slowdown in growth.
"It's true that there is a limit to what you could achieve through a traditional energy policy in one or two years," said Fridtjof Unander, an analyst with the International Energy Agency, which advises industrialized nations on ways to reduce their consumption.
The 55 miles-per-hour speed limit came as a result of the 1973 Arab oil embargo. The Nixon administration ordered states to lower their maximum limit to save fuel at a time when the first oil shock threatened to bring the economy to a standstill.
After steadily rising each year, gasoline demand suddenly stopped growing in 1974 and remained nearly flat for the next decade, keeping oil consumption in check.
Roland Hwang, the vehicles policy director at the Natural Resources Defense Council in San Francisco, estimated the savings of the speed limit in 1983 at 2.5 billion gallons of gasoline and diesel fuel, or 2.2 percent of the total use for these types of fuels.
But as gas lines faded from people's memories and energy prices went down, the federal speed limit was relaxed in 1987, allowing states to set higher caps of 65 miles an hour. Once more, gasoline consumption surged.
Smaller efforts today could make a difference. For example, driving at 10 miles an hour above the 65 miles-per-hour limit increases fuel consumption by 15 percent; inflating tires properly cuts gasoline use by 2 percent; keeping engines idle while in line wastes millions of gallons.
The trouble is that few drivers bother with these suggestions, Mr. Hwang said. "People are basically too lazy to pump their tires up."
I discovered the "sweet spot" in my 1997 Saturn SL1 while on a trip up north. (I won't say what provinces).
Did a hundred for one complete gas tank... got 45+MPG!
At 75 MPH down here I get 39 to 40 MPG.
At 65 MPH I get 41 to 42 MPG.
I don't know what it gets at 55 MPH.
The thing has 415,000+ miles on it now, still going strong without a squeek or a rattle.
But, I think if fuel prices remain relatively high, Americans will be willing to look at diesels in automobiles again, once they are made aware of the current state of diesel engines.
After all, they've been increasingly popular in light trucks in this country.
"Mr. Hwang" can kiss my grits. This is about as useful as recycling gum wrappers. Gibbering idiots.
Pumping up the tires can be a big deal as most recommended settings are based on giving a good ride and not being able to generate enough cornering force to roll the vehicle over. If your tires are below the recommended settings, they are a long way from being optimal for fuel economy. It may only be a few percent effect, but it is available for FREE. Be careful though. (;-0>
There could also be some other variables. As the Federal emissions and fuel economy tests are performed at speeds below 65, it is possible to run slightly lean at higher speeds and gain a few percentage points of engine efficiency. Note that it is difficult to fill the gas tank to the same level every fillup. A half gallon fill difference (1/4 gallon both ways) can make a big difference in the calculated fuel economy. Running tests can result in lots of variability unless the measurement system is quite capable and lots of variables are well controlled. That's one reason why they say "your mileage may vary".
The power absorbed by rolling resistance will be proportional to velocity, but the force it produces IS (roughly speaking) constant as a function of speed. Similarly, the power consumed by by aero drag is proportional to the cube of the vehicle's velocity, but the retarding force is proportional to the square of the velocity.
This 55 mph speed limit is this East Coast mentality of "we know what is best for you" and you will like this "one size fits all". Only the Easterners are so arrogant !
"Double your speed and you quadruple air resistance."
I don't plan on running 110 MPH.
Higher taxes would just make it more devastating for those of us who already can't afford gas to go to work.
I guess if he scores one, he'll just radio ahead to the rest of the trap.
For a normal vehicle that might be true if the difference in the speeds was say 60 vs. 55 but for 55 and 75 the relative velocities for a given Cd preclude that.
OK, at 75 mph then. 75 is 36% greater than 55, but the air resistance goes up to 1.362=1.86, and increase of 86 percent. It's the same principle at any speed over 55.
Another reason to despise the French, and anybody that would advocate more TAXES to encourage (FORCE) that myth called conservation.
The NY Times should save energy by shutting off their printing press.
It depends on the car. If the car has poor aerodynamics, the aero drag will overwhelmingly dominate the calculation. If the car is slippery to the air, the rolling resistance will play a larger % role until the speeds get sufficiently high for the aero drag to dominate.
But for illustrative purposes, lets assume at 55 rolling resistance and aero drag are roughly equal to each other. (That may not be exactly accurate, but it varies from car to car, and provides us with a convenient basis for our calculation.)
A 10 mph increase from 55 to 65 increases aero drag by about 40%, but since we assumed that at 55, aero drag = rolling drag = 50% of total drag, then the the total drag increases 20%.
If we go from 55 to 70, aero drag increases 61%, so total drag goes up half that: 30.5%
If we go from 55 to 75, the aero drag goes up by 85%, or total drag increases by 42.5% compared to 55....
And since fuel consumption at constant speed (assuming no hills) is proportional to the total drag, you get some idea of what happens to fuel economy as speed increases.
Caveat: the increase in drag and hence fuel consumption can be offset to some extent by design choices that will optimize fuel economy at higher engine speeds versus lower engine speeds. From a volumetric efficiency stand point, and engine produces maximum energy out per unit of the energy of the fuel used when it runs at wide open throttle at the engines torque peak. Depending on the engine/valve timing and gearing in the drive train, it is possible to have a car's engine be more fuel efficient per unit of fuel consumed at a higher speed, but this is quickly offset by the exponential rate of growth in the aero drag. Also, given the government mandated mileage tests for all models of cars, and the way they are calculated, it would make no sense for a auto manufacturer to design a vehicle with an engine/drivetrain optimised for high speed driving, because it likely would get lower ratings on the Federally mandated mileage tests than if they design it for a compromise between "City" and "highway" driving.
That said, fuel consumption just isn't an appropriate standard by which to set speed limits; safety arguably is, and if we accept safety as the prime issue in decideing speed limits, 55 is a killer on superhighways -- it's just too slow.
How does the profile figure into that calculation?
Aero drag is proportional to frontal area; if you reduce frontal area by 10% and keep the same drag coefficient, the aero drag drops by 10% (now you know why some NASCAR team once built a 9/10ths scale car, and reputedly beat the crap out of their competitors; that was one of the reasons they introduced the use of body templates, to put a stop to aerodynamic cheating).
Similarly, if your car is huge in frontal area, the effects of aero drag will begin to dominate at a slower speed than for a car with smaller frontal area.
Caveat: the above assumes vehicles with similar coefficients of drag. That's why a motorcycle, which weighs much less and has much less frontal area than a car, gets mileage that's very similar to that of a car. From the standpoint of a bunch of air molecules, a motorcycle and rider represent something like a brick trying to punch through the air, whereas modern cars have MUCH lower drag coeffecients than motorcycles. They may be bigger, and thus affect more air molecules than the motorcycle, but they abuse the air molecules much less.
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